Walking mine roof support



Feb. WW2

Filed June 30. 1964 W. WILKENLGH ETW..

WALKING MINE `ROOF SUPPORT 4 Sheets-Sheet l Feb. 7, 1967 Filed June so. 1964 w. WILKENLOH ETAL 3,302,411

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''b. WW W. WILKENLOH MAL M'WWW WALKING MINE ROOF SUPPORT [nild June 30, 1954 2 Shi-)GSWSIGS 4 United States Patent O 3,302,411 WALKING MINE RUUF SUPPORT Wilhelm Willreuloh and Karl Brauer, Duisburg-Wanheim and Manfred Koppers, Duisburg-Hamborn, Germany, assignors to Rheinstahl Wanheim GmbH., Duisburg- Wanheim, Germany Filed June 30, 1964, Ser. No. 379,135 Claims priority, application Germany, July 2, 1963, R 35,566 9 Claims. (Cl. 61--4S) The present invention relates to mine root supports in general, and more particularly to an improved mobile or walking mine roof support for use in underground coal mines and the like. Still more particularly, the invention relates to a walking mine roof support which is suitable for use in underground mines having uneven roofs and/ or floors so that the tloorand roof-engaging elements of the mine roof support must be free to move to 'a large number of different positions in order to insure satisfactory propping of the roof and to thus avoid the possibility of cavein with resultant danger to the safety of miners.

Mine roof supports of the general character to which the present invention pertains normally comprise one, two or more pairs of pit props which are provided with roof-engaging bars and Hoor-engaging sole plates, `a connecting or supporting structure whi-ch carries the props, and a motor in the form of a cylinder or the like which causes the props to advance toward the mine face. As a rule, the motor comprises a horizontal cylinder whose piston rod is connected to the customary material-removing conveyor land which causes the conveyor to advance toward the mine face when the props are disengaged from the mine roof. The conveyor extends along the mine face to collect and to remove material which is being mined, for example, coal or the like. When the conveyor has been advanced by a step and the piston rod is to be retracted in the cylinder, the props are shortened in the customary way so that their roof-engaging bars are moved to a level below the mine roof, whereupon the apparatus is free to advance by a step toward the mine face.

It is an important object of the present invention to provide a very simple, compact, easy-to-handle and very rugged walking mine roof support which may be used in underground coal mines and other types of excavations, and wherein the props and their oorand roof-engaging elements are movable with reference to each other to an extent necessary to avoid jamming and to insure that such elements may be moved in large surface-to-surface contact with the mine roof land/or mine floor.

Another object of the invention is to provide a walking mine roof support of the just outlined characteristics wherein the props, the roof-engaging elements and the floor-engaging elements are constructed and assembled in such a way that at least some thereof automatically return to optimum starting positions as soon as they become disengaged from the Walls surrounding an underground excavation.

A further object of the invention is to provide a walking mine roof support wherein the roof-engaging bars and the floor-engaging sole plates are constructed and mounted in such a way that each thereof is free to yield in response to engagement with mine roofs and/or mine floors which exhibit very large recesses, protuberances and other unevenness such as could cause damage to or breakage of parts which are not free to yield by swivelling, tilting, rocking, turning, shifting or other movement with reference to the adjacent parts of the mine roof or mine oor.

An additional object of the invention is to provide la walking mine roof support of the just outlined characteristics which may be readily and rapidly converted into Z ii Patented Feb. 7, ll-967 ICC one having two, three or even a higher number of pairwise arranged props.

A concomitant object of the instant invention is to provide a walking mine roof support wherein a damaged or deformed part may be readily and rapidly exchanged without necessitating complete dismantling of the entire apparatus, wherein the props are free to move with reference to each other (i.e., from a substantially vertical position) to an extent which is just suiicient to avoid damage to the apparatus, and wherein the props are always held against excessive oscillatory movement such as could iinpede rapid progress of the mine roof support along the mine floor and proper reengagement of bars with the mine roof.

A further object of our invention is to provide a walking mine roof support wherein the height of the floorengaging elements is rather negligible so that the center of gravity of such elements is close to the mine oor to insure great stability of the apparatus and to avoid any danger of overturning when the mine roof support is in actual use.

Another object of the invention is to provide improved connections between the main supporting structure and the props of a walking mine roof support.

An ancillaryobject of the invention is to provide a novel sole plate construction for a walking mine roof support of the above outlined characteristics.

With the above objects in view, one feature of the present invention resides in the provision of a walking mine roof support which comprises an elongated rigid supporting member preferably consisting of hollow proiiled stock (for example, a U-beam or the like) to constitute a nondeformable main assembly unit or backbone of the apparatus, a pair of leading pit props and a pair of trailing pit props arranged in such a way that the props of each Apair are disposed at the opposite sides of the supporting member, two-armed carriers secured to the main supporting member, preferably by interposition of elastic cushions and in such a way that the arms of each carrier are adjacent to one pair of props, ring-shaped guides provided on the props, and elastic or articulate connections between each guide and one arm of the respective carrier. The arms of the carriers preferably consist of elastically deformable material, such as spring steel or the like.

The upper end portion of each prop carries a plate, a bar or a similar roof-engaging element, and the lower end portion of each prop is connected with a licor-engaging sole plate. The connections between the props and the respective sole plates preferably comprise .ball and socket joints. Each prop preferably comprises a separate sole plate and such sole plates may be articulately connected to each other by means of hinges or the like. Also, the sole plates may be articulately connected with the supporting member and/or with a median sole plate carried by the supporting member. lf desired, the leading sole plates may form a rigid unit, and the trailing sole plates may form a similar rigid unit.

The novel features which are considered as character'- istic of the invention are set forth in particular in the appended claims. The improved mine roof support itself, however, both as to its construction yand its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawings, in which:

FIG. l is a side elevational view of a walking mine roof support which comprises four lpit props and five sole plates;

FIG. 2 is a side elevational View of the lower part of the mine roof support, with certain parts broken away;

FIG. 3 is a fragmentary front elevational view of the mine roof support, as seen from the left-hand side of FIG. 1 or 2;

FIG. 4 is a fragmentary top plan view of the mine roof support, with the roof bars omitted;

FIG. 5 is a side elevational view of a second walking mine roof support with four sole plates;

FIG. 6 is a front elevational view of the second mine roof support, as seen from the left-hand side of FIG. 5, with the leading sole plates shown in transverse vertical section; and

FIG. 7 is a top plan view of the second mine roof support, with the roof -bars omitted.

Referring to FIG. l, there is shown a mobile or walking mine roof support which is constructed in accordance with a rst embodiment of the present invention. The support comprises four extensible and contractible pit props including a pair of leading props l and a pair of trailing props la. As shown in FIG. 4, each leading prop 1 is aligned with one of the trailing props la, and the four props are disposed at the corners of a rectangle. Each prop comprises a lower tubular portion or cylinder and an upper tubular portion or plunger which is telescoped into the respective cylinder. The exact construction of the hydraulic circuit which controls the admission'and evacuation of oil or another pres` sure medium into and from the props forms no part of the present invention. It suices to say here that the props are caused to extend when they should support the mine roof and are caused to -contract when the mine roof support is to -advance toward the mine face. During walking (i.e., when the mine roof support is advanced toward the mine face), the four separate sole plates 4@ at the lower ends of the props I and lla shuffle along the mine oor and the roof engaging cap at the upper ends of the props is disengaged from the mine roof.

YThe roof-engaging cap comprises two pairs of elongated plate-like roof engaging members 2, 2', called roof bars, each of which is connected with the upper end portion of a prop. In the illustrated embodiment, the connection between each roof bar and the upper end portion of the respective prop comprises a universal joint including a ball 1A at the upper end of the prop and a complementary socket 2a on the respective roof bar. Such universal joints enable the roof bars 2 and 2 to follow the outline of an uneven mine roof and to insure that the area of contact between the mine roof and the roof-engaging cap is comparatively large. The trailing end portion of each leading roof `bar 2 is connected with the leading end portion of the corresponding trailing roof bar 2 by a coupling which allows the roof bars to be tilted with reference to and to be moved toward and away from each other. As shown in FIG. l, the adjacent end port-ions of aligned `roof bars 2, 2 are provided with downwardly extending flanges 2d having vertical slots 2e for a bolt 2b which :cooperates with a nut and is biased by a spring 2c which tends to maintain the roof bars 2, 2 in a common plane by biasing the flanges 2d into face-toface abutment wlith each other. The arrow C in FIG. 1 indicates the direction of forward movement of the mine roof support, i.e., the mine face is located to the left of FIG. l.

The leading roof bars 2 are provided with forwardly extending front shields 2m Iwhich yare fixed thereto by pins 2n and are held in illustrated positions by removable wedges 2p. The trailing roof bars 2 are provided with rearwardly extending rear shields 21' which keep the lling from entering the area between the props. As mentioned above, the springs 2c allow for some limited tilting and longitudinal displacement of the roof bars 2, 2 with reference to each other.

The mine roof support further comprises an elongated rigid main supporting or assembling member 3 which is spaced from the mine floor and extends between the 4 props of leading `and trailing pairs. This supporting member is a U-bar having a very high moment of resistance and is articulately coupled with the props through the intermediary of two carriers in a manner best shown in FIGS. 2 to 4. Referring first to FIG. 2, the lower tubular portions of the leading props l are received in and may be integral with sho-rt vertical cup-shaped receptacles or cups 43 lwhich are coupled to the leading sole plates 40 by a p-air 'of ball and socket joints. Each of these joints comprises a ball 41 provided at the upper side of the leading sole plate 40 and a complementary socket at the lower end of the respective cup 43. The joints further comprise suitable connectors which .insure that each ball 41 remains in but may rotate with reference to the corresponding socket. Such joints should normally allow each sole plate 40 to swivel in all directions through an angle of at least 15 degrees.

The web of the supporting member 3 carries the webs of two elastically deformable two-armed U-shaped carriers 45 which are secured thereto by bolts 46a. A layer 46 of elastic cushioning material is interposed between the web of the supporting member 3 and the web of each carrier 45 so that the latter will lhave some freedom of movement with respect to the supporting member. The upwardly extending anges or arms of each carrier 45 are connected with two ring-shaped guides 44 each of which surrounds the lower tubular portion of a prop. The connections lbetween the arms of the carriers 45 and guides 44 comprise horizontal pivot pins 44a so that the guides may be pivoted with reference to their carriers in order to insure that each prop is free to perform at least some movements Iwith reference to the supporting member 3 such as are necessary to guarantee satisfactory engagement of sole plates 40 and roof bars 2, 2 with the mine oor `and mine roof, particularly when the mine roof and/or the mine yoor is full of protuberances so that the sole plates and the roof lbars must be free to move to various positions of inclination with reference to a truly horizontal plane. The arms of the carriers 45 and t-he cushions 46 enable the lprops to move toward and away from each other. The cushions 46 also allow .for some tilting of the leading props in vertical planes which are parallel with the direction of forward movement. It can be said that each prop may swivel to a limited extent but that each thereof will automatically return to a normal vertical or nearly vertical position when the bars 2 and 2 are disengaged from the mine roof.

As shown in FIG. 3, the supporting member 3 encloses a space to accommodate a double-acting hydraulic cylinder 14 which serves as a means for advancing or walking the mine roof support toward the mine face (arrow C). As a rule, the connection between the supporting member 3 and the cylinder 14 comprises a Cardan joint. The supporting member protects the cylinder I4 against falling rock, moisture and/or dust. The overall dimensions of the member 3 are comparatively small so that the improved support is a rather compact and lightweight apparatus.

The piston rod of the cylinder 14 may move forwardly to engage a customary conveyor which extends in front of the mine roof support (at right angles to the plane of FIG. l) and is adjacent to the mine face so that the material which is ybeing removed from the mine face may accumulate on and is automatically removed by the conveyor. Before the piston rod of the cylinder 14 performs a forward stroke, the bars 2 and 2' are caused to engage the mine roof so that the mine roof support remains stationary but the conveyor is caused to advance by a step so as to move nearer to the mine face. In the next step, the props 1, 1a are caused to contract and the piston rod is retracted into the cylinder 14 whereby the sole plates 4t) slide along the mine floor and the entire mine roof support moves nearer to the mine face (arrow C in FIG. 1). Such manner of walking the mine roof support and the conveyor is well known in the art and, therefore, the conveyor has not been shown in the drawings.

lt will be noted that the upper sides of the sole plates 40 are practically free of any protruding parts which would be likely to retain pieces of falling rock or the like. This is important because such falling debris could cause jamming of the mine roof support. Also, the articulate connections between the supporting member 3, the props 1, 1a and sole plates 40 are just suicient to allow for tilting of such parts with reference to the supporting member but will not allow excessive tilting such as could result in excessive swinging of props when the mine roof support advances toward the mine face. Excessive tilting is undesirable because the props should rapidly return to substantially vertical positions in which they are ready to move the roof bars 2, 2' back in supporting engagement with the mine roof. In other words, swinging or tilting of the props from a vertical or nearly vertical position should be kept to a permissible minimum.

The four separate sole plates 40 are articulately connected with a holder here shown as a fifth or median sole plate 42, for example, by means of hinges 42a. The median sole plate or holder 42 extends transversely between the leading -and trailing props and comprises upwardly extending brackets 42b which are preferably rigidly fixed to the supporting member 3. The guides 44 are located at a level above the supporting member. The arms of the carriers 45 consist of spring steel. `Each of these arms is provided with an upwardly extending open slot 45a to receive the pivot pin 44a of the corresponding guide 44. Such connections between the supporting member 3 and the props 1, 1a enable the sole plates 40` to be tilted to many different positions of inclination in order to make sure that each sole plate lwill be in large surfaceto-surface contact with the mine floor. Also, the props are free to move vertically, to move into 4inclined positions not only with reference to each other but also with respect to the supporting member 3. Such universal movability of the sole plates and props is necessary to avoid jamming when the m-ine roof support is used on uneven mine floors and/or when the roof bars 2 and 2 must engage an uneven mine roof. FIG. 2 illustrates by broken lines various positions of inclination which the sole plates 40 may assume on uneven terrain.

The mine roof support of FIGS. 1 to 4 further comprises a pair of lifting devices which serve to lift the front end portions of the leading sole plates 40. Each of these lifting devices comprises a cylinder 47 whose upper end is connected with a bracket 48 secured to one of the leading props 1, a piston whose piston rod 49 is reciprocable in the respective cylinder and is articulately connected with the respective leading sole plate 40 by a horizontal pivot pin 51, and a spring 50 which tends to move the piston rod 49 upwardly and to thereby lift the front end portion of the respective leading sole plate. The lifting devices insure that the leading sole plates cannot be hurried in the material of the mine floor and ltend to rotate the leading sole plates in a clockwise direction, as viewed in FIG. 2. It will tbe noted that the front end portions of the leading sole plates 40 are bent upw-ardly so that each of these sole plates resembles a runner.

Referring now to FIGS. 5 to 7, there is shown a second walking mine roof support wherein the lower end portions of the props 1 and la are provided with balls 53 which are received in suitable sockets 52a provided at the upper sides of the sole plates 52. The sockets 52a resemble flanged rings which are welded to the respective sole plates. The arrangement is preferably such that each ball 53 forms with the corresponding socket 52a a universal joint which enables the respective prop 1 or 1a to swivel in all directions through an angle of at least degrees.

Each sole plate 52 is coupled to the supporting member 3 by a hinge 54 whose pintle is horizontal and extends at right angles to the longitudinal extension of the supporting member, i.e., at right angles to the direction of forward movement of the mine roof support (arrow C). Each pair of adjacent sole plates 52 is connected to each other by a horizontal hinge 55 whose pintle is parallel with the longitudinal extension of the supporting member 3. It goes without saying that the pairs of leading or trailing sole plates may be replaced by a single leading or trailing sole plate, or that the leading sole plates 52 or the trailing sole plates 52 may be rigidly connected rwith each other.

The lower .tubular portion of each prop is received in a ring-shaped guide 56 having an inwardly extending bracket or lug 56a which is secured to one of two transversely extending two-armed carriers 57. These carriers consist of spring steel to allow for rat least some tilting of the props 1 and 1a' with reference to each other. The connections between the median portions of the carriers 57 and t-he web of the main supporting member 3 comprise elastic cushions 58. The arms of the carriers 57 are substantially horizontal.

It is to be understood that certain features described in connection wit-h FIGS. l to 4 may be embodied in the mine roof supports of FIGS. 5 to 7' or vice versa.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of t-he generic and speci'c aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In the walking mine roof support, in combination, an elongated substantially horizontal rigid supporting member; a pair of leading pit props; a pair of trailing pit props, the props of each pair being disposed at the opposite sides of said supporting 'member and each having ,an upper and a lower end portion; roof-engaging members connected with the upper end portions of said props; floor-engaging sole plates articulately connected with the lower end portions of said props; two-armed carriers secured to said supporting member, one for earch pair of props, said carriers being disposed at a fixed distance from each other; a guide provided for each of said props; connecting means securing each of said guides to one arm of the respective carrier, each prop being reciprocable up and down in the respective guide; and advancing means for moving said supporting member lengthwise.

2. A structure as set forth in clai-m 1, wherein said supporting member consists of hollow proled st-ock and said advancing means comprises a cylinder mounted in said supporting member.

3. A structure as set forth in clai-m 1, wherein said connecting means provides pivotable connections between said guides and the respective carriers.

4. A structure as set forth in claim 1, wherein the arms of said carriers are elastic.

5. A structure as set forth in claim 1, further comprising a plate-like holder extending transversely between said pairs olf props and fixedly secured to said supporting member, zand hinge means articulately connecting said holder with said sole plates.

6. A structure as set forth in claim 1, further comprising first hinge means articulately connecting the sole plates of said leading props and second hinge means articulately connecting the sole plates of said trailing props.

7. A structure as set forth in claim 1, wherein the sole plates of said leading props comprise front end portions extending forwardly of the respective props, and further comprising.)1 lifting means larranged to exert an upward pull on said front end portions.

8. A structure .as set forth in claim 1, wherein said guides are disposed at a level above said supporting member.

9. A structure as set forth in claim 1, wherein said connecting means comprises elastic cushions and where in said guides resemble rings `surrounding portions of the respective props.

References Cited by the Examiner UNITED STATES PATENTS 3,201,943 8/1965 Wilkenloh et al 61--45-2 5 FOREIGN PATENTS 1,361,408 4/ 1964 France.

CHARLES E. OCONNELL, Prnmry Examiner.

10 JACOB SHAPIRO, Examiner. 

1. IN THE WALKING MINE ROOF SUPPORT, IN COMBINATION, AN ELONGATED SUBSTANTIALLY HORIZONTAL RIGID SUPPORTING MEMBER; A PAIR OF LEADING PIT PROPS; A PAIR OF TRAILING PIT PROPS, THE PROPS OF EACH PAIR BEING DISPOSED AT THE OPPOSITE SIDES OF SAID SUPPORTING MEMBER AND EACH HAVING AN UPPER AND A LOWER END PORTION; ROOF-ENGAGING MEMBERS CONNECTED WITH THE UPPER END PORTIONS OF SAID PROPS; FLOOR-ENGAGING SOLE PLATES ARTICULATELY CONNECTED WITH THE LOWER END PORTIONS OF SAID PROPS; TWO-ARMED CARRIERS SECURED TO SAID SUPPORTING MEMBER, ONE FOR EACH PAIR OF PROPS, SAID CARRIERS BEING DISPOSED AT A FIXED DISTANCE FROM EACH OTHER; A GUIDE PROVIDED FOR EACH OF SAID PROPS; CONNECTING MEANS SECURING EACH OF SAID GUIDES TO ONE ARM OF THE RESPECTIVE CARRIER, EACH PROP BEING RECIPROCABLE UP AND DOWN IN THE RESPCTIVE GUIDE; AND ADVANCING MEANS FOR MOVING SAID SUPPORTING MEMBER LENGTHWISE. 